1. Field of the Invention
This invention relates to an apparatus for reducing the fluid pressure within a hydraulic circuit in order to enable a male coupler element to be more easily coupled to a female coupler element.
2. Description of the Related Art
Hydraulic cylinders are employed on many types of farm equipment such as cultivators, harrows, discs, plows, etc., in order to raise and lower the earth engaging |members thereof. In most cases, the hydraulic cylinders of such equipment have one or more hydraulic hoses or lines fluidly connected thereto for extending and retracting the cylinder rod thereof. The free end of the hose or hoses normally has a male coupler element connected thereto which is adapted to be quickly coupled to a female coupler element which is in fluid communication with the source of hydraulic fluid which is usually located on the prime mover such as a tractor or the like. The male coupler element includes a normally closed, spring-loaded, ball check valve. The female coupler element also frequently has a normally closed, spring-loaded, ball check valve. When the male and female coupler elements are coupled together, the ball check valves therein are open to permit the flow of hydraulic fluid therethrough. When the male coupler element is disconnected from the female coupler element, the ball check valve therein automatically closes to prevent the escape of hydraulic fluid from the hose and cylinder. As the male coupler element is being coupled to the female coupler element, it is necessary that sufficient force be applied to unseat the ball check valve in the male coupler element so that hydraulic fluid may pass through the male coupler element. Even in xe2x80x9cnormalxe2x80x9d conditions, it is sometimes difficult to couple the male and female coupler elements together due to the spring resistance of the ball check valve in the male coupler element. Further, when the coupler elements have been disconnected and the hydraulic cylinder and hose have been subjected to warm temperatures, the hydraulic fluid in the cylinder and hose expands thereby causing an increase in the hydraulic fluid pressure within the hose which additionally resists the opening movement of the ball check valve in the male coupler element during the coupling operation. Additionally, when the ground engaging elements of the implement have been raised out of ground engagement before the coupling elements have been disconnected, the weight of the ground engaging elements imposed on the cylinder may also increase the hydraulic fluid pressure within the cylinder and hose thereby making the coupling process more difficult.
In all situations where hydraulic pressure is present within the hydraulic hose prior to the coupling operation, the possibility of fluid spillage from the coupling elements is great. Although the situations described above relate to farm implements, the same problems exist whenever male coupler elements are coupled to female coupler elements such as on truck-trailer combinations, etc.
An apparatus is provided for reducing the fluid pressure within a hydraulic circuit which includes a conventional male coupler having a normally closed, ball check valve therein. The apparatus of this invention comprises an auxiliary female coupling element having a first end and a second end which are in fluid communication with each other. The first end of the auxiliary coupler element includes a female portion adapted to detachably receive the male coupler element therein so that the male coupler element is coupled to said auxiliary coupler element. A hydraulic fluid reservoir is in fluid communication with the auxiliary coupler element. A selectively movable actuator extends into the auxiliary coupler element for selective engagement with the ball check valve in the male coupler element when the coupler elements are coupled together so that the ball check valve may be at least partially opened to permit a portion of the hydraulic fluid in the hydraulic line to bypass the ball check valve and to flow into said reservoir, thereby reducing the fluid pressure within the hydraulic line. In the preferred embodiment, the selectively movable actuator comprises an elongated rod which is threadably mounted in the auxiliary coupler element.
It is therefore a principal object of the invention to provide an improved apparatus for reducing the fluid pressure within a hydraulic circuit or line;
Still another object of the invention is to provide a convenient means for draining hydraulic fluid from a hydraulic line or circuit so that the pressure within the hydraulic line or circuit is reduced without the spillage of hydraulic fluid.
Still another object of the invention is to provide a device of the type described which is easy to use.
Still another object of the invention is to provide a portable auxiliary coupler unit which may be easily carried and/or stored for use on many different hydraulic circuits.
These and other objects will be apparent to those skilled in the art.